Device for converting a linear movement in a stationary system into a rotational movement about a pivot axis in a system which rotates about a rotational axis

ABSTRACT

A conversion device for converting linear movement in a stationary system into rotary movement about a pivot axis in a system which rotates about an axis of rotation that is not identical or parallel to the pivot axis. The conversion device has a lift element and a lift device with which the lift element can be moved with translatory movement relative to the stationary system. The lift element has first and second lift element portions connected together by a rotary bearing so that the first lift element portion can be rotated relative to the second lift element portion about the axis of the rotary bearing. The first lift element portion is connected to the lift device and the second lift element portion is connected to the conversion device. The conversion device is connected to a shaft positioned on the pivot axis so that a linear movement of the second lift element portion is converted into a rotary movement of the shaft about the pivot axis.

The present invention concerns a device for converting a linear movementin a stationary system into a rotary movement about a pivot axis in asystem rotating about an axis of rotation.

There are a large number of applications in which in a rotating system,an element rotating therewith is to perform a pivotal movement about apivot axis, wherein the pivot axis does not extend on the axis ofrotation and is also not parallel thereto. To produce the pivotalmovement a suitable drive is required. In that case the drive can beprovided in the rotating system so that it also rotates therewith.However the drive has to be supplied with power and in addition itrequires space appropriately by virtue of the arrangement in therotating system. Particularly when the drive is of a high mass or therotating system rotates about the axis of rotation at high rotary speedsbalancing elements are required under some circumstances to compensatefor the weight of the drive.

An application by way of example is a mixer having a mixing containerwhich rotates during the mixing process and in which the mixing materialis accommodated. Such mixers frequently have eccentrically arrangedmixing tools which themselves can again be rotated in operation. Aclosure cover is arranged in the bottom of the mixing container foremptying the mixer after the mixing operation has taken place. Such amixer is known for example from WO 2011/128435 A1.

In the structure shown therein the closure cover is connected to acarrier arm by way of a mounting yoke and a mounting journal and canthus be pivoted about the tilt axis of the mounting journal. In suchmixers the closure cover frequently terminates flush with the bottom ofthe container so that a flat bottom surface on which the mixing materialis moved is formed. That ensures efficient thorough mixing of all themixing material as there is no dead space above the closure cover, whichis not reached by the mixing tool.

The requirement for the closure cover to end flush with the containerbottom causes difficulties in terms of the design configuration andguidance of the closure cover.

Basically the closure cover would have to firstly be moved linearlydownwardly to open the emptying opening. That however would have theresult that, by virtue of the emptying opening being arranged in thebottom of the container, the mixing material would flow over all edgesurfaces of the closure cover and possibly even contaminate the drive ofthe closure cover. Exclusively lateral pivotal movement of the closurecover out of the emptying opening is however not possible by virtue ofthe substantially cylindrical or frustoconical contact surfaces of theclosure cover and the emptying opening.

For that reason the drive of the closure cover, that is disclosed in WO2011/128435 A1,allows a pivotal movement both about the pivot shaft andalso about the mounting journal. In the described embodiment the carrierarm is positioned in the stationary system while the closure coverrotates together with the container in the state of being fitted intothe emptying opening. The closure cover is therefore mounted rotatablyon the carrier arm.

In principle it would be advantageous if the closure cover has to bepivoted only about a pivot axis for opening or closing thereof. In ordernonetheless to provide that it terminates flush in the bottom of thecontainer the edge surfaces of the closure element would have to be of acurved configuration in such a way that they are on a notional sphere sothat, for opening and closing the emptying opening, the closure elementcould be pivoted about its pivot axis extending through the centre pointof the notional sphere.

In that case however it is not possible for the closure cover to bedesigned to rotate relative to a carrier arm. Instead the drive wouldhave to be moved into the rotary system with the above-describeddisadvantages. Hitherto therefore the closure cover has not beenimplemented in the described form.

The object of the present invention is therefore to provide a device forconverting a linear movement in a stationary system into a rotarymovement about a pivot axis in a system which rotates about an axis ofrotation. An object of the present invention is also to provide a mixingdevice of the described kind, in which the closure cover can be pivotedabout a pivot axis, wherein the drive for same is positioned in thestationary system.

According to the invention that object is attained by a conversiondevice of the described kind, which has a lift element, a lift devicewith which the lift element can be moved with a translatory movementrelative to the stationary system, and a device for converting a linearmovement into a rotary movement. In that case the lift element has afirst lift element portion and a second lift element portion, whereinthe two lift element portions are connected together by way of a rotarybearing in such a way that the first lift element portion can be rotatedabout the axis of the rotary bearing relative to the second liftportion, wherein the two portions of the lift element are connectedtogether in positively locking relationship in the direction of thetranslatory movement of the lift device, and the first lift elementportion is connected to the lift device while the second lift elementportion is connected to the device for converting a linear movement intoa rotary movement so that the device for converting a linear movementinto a rotary movement is connected to a shaft positioned on the pivotaxis in such a way that a linear movement of the second lift elementportion is converted into a rotary movement of the shaft about the pivotaxis.

Thus a lift device and a lift element are arranged in the stationarysystem. By means of the lift device the lift element can be linearlyreciprocated between two positions, namely a lower position and an upperposition. The terms ‘lower’ and ‘upper’ are randomly selected here. Inprinciple instead of being in a vertical direction the movement of thelift device could also take place in a horizontal direction or in anyother desired direction.

In a preferred embodiment the movement of the lift device is parallel tothe axis of rotation of the rotating system.

The lift device is the drive in the stationary system, that canreciprocate only the lift element between two positions. The liftelement itself comprises two portions, the first lift element portionand the second lift element portion. The first lift element portion isnon-rotatably connected to the lift device. The second lift elementportion is in turn connected to the first lift element portion by way ofa rotary bearing so that the second lift element portion can be rotatedrelative to the first lift element portion about the axis of the rotarybearing. In a preferred embodiment the axis of the rotary bearing lieson the axis of rotation of the rotating system.

The result of the structure described hitherto is that the second liftelement portion can rotate relative to the first lift element portionabout the axis of rotation while at the same time the lift device canreciprocate the first lift element in the direction of the axis ofrotation.

The second lift element portion is now connected to the device forconverting a linear movement into a rotary movement. By virtue of thefact that the second lift element portion also reciprocates togetherwith the first lift element portion in the direction of the axis ofrotation by virtue of the positively locking connection to the firstlift element portion this involves a linear movement of the second liftelement portion. The device for converting a linear movement into arotary movement is connected to the second lift element portion and isthus also in the rotating system. A shaft which is positioned on thepivot axis and which is connected to the device for converting a linearmovement into a rotary movement is always rotated about the pivot axiswhen the lift device performs a linear movement.

A preferred embodiment provides that the lift device has at least oneand preferably at least four lift pistons which connects the stationarysystem to the first lift element portion and can linearly move the firstlift element portion relative to the stationary system.

In a further preferred embodiment the first and/or the second liftelement portion are of an annular configuration. For example the secondlift element portion can include a cylindrical discharge passage of amixing container and rotate with same about the axis of rotation.

In a further preferred embodiment it is provided that the device forconverting a linear movement into a rotary movement has a cam plateconnected to the second lift element portion and a lever which is incontact with the cam plate and which is connected to a shaft arranged onthe pivot axis.

It has been found that this embodiment is particularly practicable evenif other devices for converting the translatory movement into a rotarymovement like for example a gear-rack combination are conceivable.

In a further preferred embodiment there is provided a further device forconverting a linear movement into a rotary movement, that is connectedto the second lift element portion and a second shaft arranged on thepivot axis. In that way the shaft positioned on the pivot axis can be ofa two-part structure to keep clear for example the opening region inwhich the pivot axis is disposed.

In regard to the mixing device the object set forth in the opening partof this specification is attained in that there is provided a mixingdevice having a container for receiving mixing material, that isrotatable about a container axis and in the bottom of which is arrangedan emptying opening. The mixing device has a closure cover for closingthe emptying opening and a mixer foot, the container being rotatablerelative to the mixer foot. According to the invention there is now useda conversion device as just described, in which the mixer foot is partof the stationary system and the container is part of the rotatingsystem, wherein the closure cover can be rotated about a pivot axis foropening and closing the emptying opening.

In a particularly preferred embodiment of the mixing device it has twodevices for converting a linear movement into a rotary movement, whichare both connected to the second lift element portion, wherein both arerespectively connected to a shaft arranged on the pivot axis. In thatway it is now possible for the closure cover to comprise two closurecover portions which can be reciprocatingly pivoted about a pivot axisrelative to each other between a closed position in which the twoclosure cover portions are in contact and together form the closurecover and an opened position in which the two closure cover portions arespaced from each other so that an opening for removing the mixingmaterial from the container is formed between the two closure coverportions in order to reciprocate them between the closed position andthe opened position. In that case both closure cover portions arepivotable about the same pivot axis, wherein the one closure coverportion is connected to the device for converting a linear movement intoa rotary movement and the other closure cover portion is connected tothe further device for converting a linear movement into a rotarymovement.

Advantageously the mixing device has a rotatable mixing tool arranged inthe interior of the container. The closure element can have an innersurface which when the emptying opening is closed is arranged within thecontainer, an outer surface which when the emptying opening is closed isarranged outside the container, and an edge surface which when theemptying opening is closed is arranged opposite an edge surface of theemptying opening.

In a preferred embodiment the closure element, the emptying opening andthe pivot axis are of such a configuration and arrangement that a pointarranged furthest from the pivot axis describes a circle on the innersurface or the edge surface of the closure element in the pivotalmovement, wherein the closure element is arranged within the circle andthe edge surfaces of the emptying opening are arranged outside thecircle.

By virtue of that measure the closure element only has to be rotatedabout the pivot axis to close the emptying opening. The emptying openingis of such a configuration and arrangement that the edge surfaces of theemptying opening cannot collide with the closure element during thepivotal movement.

In principle a gap can remain between the edge surfaces of the closureelement and the edge surfaces of the emptying opening even in the closedposition of the closure element within the emptying opening. The gapwidth however should be less than the smallest grain size of the mixingmaterial to be processed, to prevent the mixing material from flowingout of the mixing container in the closed position of the closureelement.

A preferred embodiment provides that the emptying opening and theclosure element have mutually corresponding edge surfaces which comeinto contact with each other when the closure element is positioned inthe emptying opening.

That measure ensures that no gap remains between the emptying openingand the closure element in the closed position of the closure cover.

A further preferred embodiment provides that the edge surfaces of theclosure element are of a curved configuration such that they lie on anotional sphere and the centre point of the notional sphere lies on thepivot axis.

Particularly preferably the closure element ends flush with the bottomso that a flat bottom surface is afforded when the closure element ispositioned in the emptying opening.

Such a configuration of the edge surfaces is similar to the structure ofspherical segment valve members. Spherical segment valve members serveas a shut-off member within dosing and feed lines. It will be notedhowever that in the case of the spherical segment valve members themovable valve members are of a spherical segment shape, that is to saynot only the contact surfaces which come into contact with acorresponding valve seat are of a curved configuration, but the entirevalve member is in the shape of a spherical cap. Apart from the factthat such a valve member is not to be viewed as a closure cover, it alsodoes not permit a flat arrangement in the container bottom by virtue ofthe cap shape.

The configuration according to the invention has the advantage that theclosure cover can be easily pivoted about the pivot axis to close oropen the emptying opening.

Further advantages, features and possible uses of the present inventionwill be apparent from the description hereinafter of a preferredembodiment and the associated Figures.

In the Figures:

FIG. 1 shows a lateral section through a mixer with closure cover anddevice for operating the closure cover according to the presentinvention,

FIG. 2 shows a plan view of the closure region of FIG. 1,

FIG. 3 shows a second plan view of the closure region of FIG. 1, and

FIG. 4 shows a sectional view of the closure region of FIGS. 1 to 3 witha multi-part closure cover.

FIG. 1 shows a section through a mixer with a device according to theinvention. The cylindrical mixing container 1 has a mixing tool 2 whichis arranged eccentrically in the mixing container and which is supportedin overhung relationship on a central mixer shaft 3 as well as astationary wall/bottom scraper (not shown) mounted vertically inoverhung relationship from above. Fixed to the lowermost plane of themixing tool 2 are vertically downwardly projecting bottom blades 4 whichoperate at a small spacing relative to the surface of the containerbottom.

The emptying opening 5 is in the centre of the mixing container 1. Theemptying opening can be closed with the closure element in the form of aclosure cover 6. The mixing container bottom 7 can be seen here.

The container bottom 7 rotates together with the container about an axisof rotation 8. The closure cover portion 6 is rotated about the pivotaxis 9 for opening and closing the closure cover 6. So that this ispossible the emptying opening and the closure cover portions preferablyhave mutually corresponding edge surfaces curved in such a way that theylie on a notional sphere so that, for opening or closing the emptyingopening, the closure element portions can be pivoted about a pivot axison which the centre point of the notional sphere lies.

In general disposed in the mixing container arranged above the mixingcontainer bottom 7 is mixing material which, when the closure cover 6 isopened, falls into the mixing material discharge 10 through the emptyingopening 5. The mixing material discharge 10 is connected to thecontainer bottom so that same rotates with the container. Arranged onthe mixing material discharge 10 is a skirt 11 connected to thestationary system. The mixing material discharge 10 and the skirt 11 arerotatable relative to each other by way of a rotary bearing 16.

A lift device 12, 13 is also arranged connected to the stationarysystem, that is to say for example in the mixer base, in which thecorresponding mixer is positioned. In the illustrated example two liftstroke pistons 13 are arranged in the corresponding chambers within thepiston housing 12. In per se known manner the fluid chambers formed bythe lift pistons 13 can be acted upon with pressure fluid within thepiston housing 12 in order to reciprocate the lift piston 13 within thehousing 12 between its two extreme positions shown for example in FIGS.2 and 3.

The lift piston 13 is connected to a first lift element portion 14. Whenthe lift device 12, 13 is actuated the lift element portion 14 can bemoved upwardly and downwardly together with the lift piston 13. The liftelement comprises the first lift element 14 and the second lift element15. The two lift element portions 14, 15 are rotatable relative to eachother by way of a rotary bearing 16. As the first lift element 14 isfixed to the lift piston 13, that is arranged in the stationary system,that is to say it does not rotate together with the mixing container.The second lift element portion 15 in turn is connected to the mixingmaterial discharge 10 so that it rotates together with same and themixing container when the container is driven. The first lift elementportion and the second lift element portion are so arranged that theyare connected together in positively locking relationship in thedirection of the linear movement of the lift device 12, 13, which meansthat, when the first lift element 14 is moved from the lower positionshown in FIG. 2 into the upper position shown in FIG. 5, the second liftelement portion 15 is also lifted.

As can be seen in particular from FIGS. 2 and 3 a cam plate 17 isconnected to the second lift element portion 15. A lever 18 runs on thecam plate, in turn being connected to the mixing container or the mixingmaterial discharge 10. When now the lift device is actuated to move thelift element from the lower FIG. 2 position into the upper FIG. 3position the lever 18 runs along the cam plate 17 and is rotated in theclockwise direction about the pivot axis 9. As the pivotal shaft 19 onthe pivot axis 9 is connected to a closure cover 6 the latter is alsorotated about the pivot axis 9.

FIG. 4 shows a sectional view of the closure region of FIGS. 1 to 3 witha multi-part closure cover. In this case the second lift element portion15 has two devices 17′, 17″ and 18′, 18″ for converting a linearmovement into a rotary movement, that are both connected to the secondlift element portion 15. Disposed in opposite relationship cam plates17′ and 17″ are connected to the second lift element portion 15. The camplates 17 and 17″ are preferably identical for the mutually oppositemovement of the closure cover portions 6′ and 6″ (not shown), that is tosay they are not of a mirror-image symmetrical configuration. Anappropriate lever 18′ and 18″ respectively runs in the cam plates,wherein both levers are respectively connected to a pivotal shaft 19′and 19″ which is arranged on the pivot axis, the levers in turn beingrespectively connected to the closure cover portion 6′ and 6″respectively associated with the pivotal shaft. In that way it is nowpossible for the closure cover to comprise two closure cover portions 6′and 6″ which can be reciprocated relative to each other between a closedposition and an opened position about a pivot axis to reciprocate thembetween the closed position and the opened position. In that arrangementboth closure cover portions are pivotable about the same pivot axis 9,wherein the one closure cover portion 6′ is connected to the device 17,18′, 19′ for converting a linear movement into a rotary movement and theother closure cover portion 6″ is connected to the further device 17″,18″, 19″ for conversion of a linear movement into a rotary movement.When using identical cam plates 17′ and 17″ the one pivotal shaft 19′then pivots in the clockwise direction while the second pivotal shaft19″ disposed on the same pivot axis 9 is moved in the anti-clockwisedirection.

By virtue of the described conversion device it is possible in a simplefashion for a pivotal movement to be produced within a rotating systemfrom a stationary system by means of a translatory movement.

LIST OF REFERENCES

-   1 mixing container-   2 mixing tool-   3 mixer shaft-   4 bottom blade-   5 emptying opening-   6 closure cover-   6′, 6″ closure cover portion-   7 mixing container bottom-   8 axis of rotation-   9 pivot axis-   10 mixing material discharge-   11 skirt-   12 piston housing-   13 lift device-   14 first lift element-   15 second lift element-   16 rotary bearing-   17 cam plate-   18 lever-   19, 19′, 19″ pivotal shaft

1. A device for converting a linear movement in a stationary system intoa rotary movement about a pivot axis in a system which rotates about anaxis of rotation, wherein the pivot axis and the axis of rotation arenot identical and do not extend parallel to each other, whereinpreferably the pivot axis and the axis of rotation extendperpendicularly to each other, comprising a lift element, a lift devicewith which the lift element can be moved with a translatory movementrelative to the stationary system, and a device for converting a linearmovement into a rotary movement, wherein the lift element has a firstlift element portion and a second lift element portion, wherein the twolift element portions are connected together by way of a rotary bearingin such a way that the first lift element portion can be rotatedrelative to the second lift element portion about the axis of the rotarybearing, wherein the two portions of the lift element are connectedtogether in positively locking relationship in the direction of thetranslatory movement of the lift device, wherein the first lift elementportion is connected to the lift device and the second lift elementportion is connected to the device for converting a linear movement intoa rotary movement, wherein the device for converting a linear movementinto a rotary movement is connected to a shaft positioned on the pivotaxis in such a way that a linear movement of the second lift elementportion is converted into a rotary movement of the shaft about the pivotaxis, wherein the device for converting a linear movement into a rotarymovement has a cam plate connected to the second lift element portionand a lever which is in contact with the cam plate and which isconnected to the shaft.
 2. The conversion device according to claim 1,wherein the lift device has at least one and preferably at least fourlift pistons which connects the stationary system to the first liftelement portion and can linearly move the first lift element portionrelative to the stationary system.
 3. The conversion device according toclaim 1, wherein the first and/or the second lift element portion is ofan annular configuration.
 4. (canceled)
 5. The conversion deviceaccording to claim 1, wherein there is provided a further device forconverting a linear movement into a rotary movement, that is connectedto the second lift element portion and a second shaft arranged on thepivot axis.
 6. The conversion device according to claim 5, wherein thetwo devices for converting a linear movement into a rotary movement areof such a configuration that the two shafts arranged on the pivot axisare moved in mutually opposite relationship.
 7. A mixing devicecomprising a container for receiving mixing material, which is rotatableabout a container axis and in the bottom of which is arranged anemptying opening, a closure cover for closing the emptying opening and amixer foot the container being rotatable relative to the mixer foot; andthe conversion device according to claim 1, in which the mixer foot ispart of the stationary system and the container is part of the rotatingsystem, wherein the closure cover can be rotated about a pivot axis foropening and closing the emptying opening.
 8. The mixing device accordingto claim 7, wherein the conversion device further includes a furtherdevice for converting a linear movement into a rotary movement that isconnected to the second lift element portion and a second shaft arrangedon the pivot axis, the closure cover comprises two closure coverportions which can be reciprocatingly pivoted about a pivot axisrelative to each other between a closed position in which the twoclosure cover portions are in contact and together form the closurecover and an opened position in which the two closure cover portions arespaced from each other so that an opening for removing the mixingmaterial from the container is formed between the two closure coverportions in order to reciprocate them between the closed position andthe opened position, wherein both closure cover portions are pivotableabout the same pivot axis, wherein the one closure cover portion isconnected to the device for converting a linear movement into a rotarymovement and the other closure cover portion is connected to the furtherdevice for converting a linear movement into a rotary movement.
 9. Themixing device according to claim 7, wherein the emptying opening and theclosure element have mutually corresponding edge surfaces which comeinto contact with each other when the closure element is positioned inthe emptying opening, wherein preferably the edge surfaces of theclosure element are of a curved configuration such that they lie on anotional sphere and the centre point of the notional sphere lies on thepivot axis.
 10. The mixing device according to claim 7 the closureelement terminates flush with the bottom so that a flat bottom surfaceis afforded when the closure element is positioned in the emptyingopening.